Temperature Dependent Dielectric Properties of Polycrystalline Aluminum Oxide Substrates with Various Impurities

Temperature dependent dielectric properties of 92% and 99.6% polycrystalline aluminum oxide (Al₂O₃) substrate materials between room temperature and 550degC are reported, and compared with those of 96% Al₂O₃. Parallel-plate capacitors with aluminum oxide dielectrics and gold electrodes were used for measurement of the dielectric properties of these materials. The capacitance and parallel conductance of these Al₂O₃ materials were directly measured by an impedance meter at 120 Hz. 1 KHz. 10 KHz. 100 KHz. and 1 MHz. and the dielectric constant and dielectric loss were calculated from the measured capacitance and conductance data. The temperature and frequency dependent quality factor (dissipation factor) of these materials are presented.